Move SkGLContext and some GrGLInterface implementations to skgputest module

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1815823002
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot

Committed: https://skia.googlesource.com/skia/+/fe3456cb006110d045b26ff3f8681b893a757b58

Review URL: https://codereview.chromium.org/1815823002
diff --git a/tools/gpu/gl/debug/GrBufferObj.h b/tools/gpu/gl/debug/GrBufferObj.h
new file mode 100644
index 0000000..96aef6e
--- /dev/null
+++ b/tools/gpu/gl/debug/GrBufferObj.h
@@ -0,0 +1,76 @@
+
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrBufferObj_DEFINED
+#define GrBufferObj_DEFINED
+
+#include "GrFakeRefObj.h"
+#include "gl/GrGLDefines.h"
+
+////////////////////////////////////////////////////////////////////////////////
+class GrBufferObj : public GrFakeRefObj {
+    GR_DEFINE_CREATOR(GrBufferObj);
+
+public:
+    GrBufferObj()
+        : GrFakeRefObj()
+        , fDataPtr(nullptr)
+        , fMapped(false)
+        , fBound(false)
+        , fSize(0)
+        , fUsage(GR_GL_STATIC_DRAW) {
+    }
+    virtual ~GrBufferObj() {
+        delete[] fDataPtr;
+    }
+
+    void access() {
+        // cannot access the buffer if it is currently mapped
+        GrAlwaysAssert(!fMapped);
+    }
+
+    void setMapped(GrGLintptr offset, GrGLsizeiptr length) {
+        fMapped = true;
+        fMappedOffset = offset;
+        fMappedLength = length;
+    }
+    void resetMapped()           { fMapped = false; }
+    bool getMapped() const       { return fMapped; }
+    GrGLintptr getMappedOffset() const { return fMappedOffset; }
+    GrGLsizeiptr getMappedLength() const { return fMappedLength; }
+
+    void setBound()              { fBound = true; }
+    void resetBound()            { fBound = false; }
+    bool getBound() const        { return fBound; }
+
+    void allocate(GrGLsizeiptr size, const GrGLchar *dataPtr);
+    GrGLsizeiptr getSize() const { return fSize; }
+    GrGLchar *getDataPtr()       { return fDataPtr; }
+
+    void setUsage(GrGLint usage) { fUsage = usage; }
+    GrGLint getUsage() const     { return fUsage; }
+
+    void deleteAction() override;
+
+protected:
+private:
+
+    GrGLchar*    fDataPtr;
+    bool         fMapped;       // is the buffer object mapped via "glMapBuffer[Range]"?
+    GrGLintptr   fMappedOffset; // the offset of the buffer range that is mapped
+    GrGLsizeiptr fMappedLength; // the size of the buffer range that is mapped
+    bool         fBound;        // is the buffer object bound via "glBindBuffer"?
+    GrGLsizeiptr fSize;         // size in bytes
+    GrGLint      fUsage;        // one of: GL_STREAM_DRAW,
+                                //         GL_STATIC_DRAW,
+                                //         GL_DYNAMIC_DRAW
+
+    typedef GrFakeRefObj INHERITED;
+};
+
+#endif // GrBufferObj_DEFINED